A brief plumbing diversion

Pulling out your Dremel during plumbing work is probably a mistake.  I should have pulled out the WD-40 first, but I didn't.  I probably could have gotten the faucet valve off without the Dremel, but I'll never know for sure. What I do know for sure is that no one makes those types of valves anymore.

It started so innocently.  I had some extra time between Christmas and New Years, and my bathroom sink faucet was dripping.  It seemed like a good time to fix the sink, rather than the beginning of a journey down a dead end tree in plumbing's evolutionary past.  A view into an alternative reality that sucks.  I knew that the sink was old --- probably 90 years old --- but I hadn't thought through what that meant.

When my wife told me it was a Crane sink, I didn't give it a second's thought, because I'd never heard of Crane.  There is a reason you've never heard of Crane sinks --- they're so badly designed for maintenance that it boggles the mind and most people simply junk them.  I've been writing software for 31 years, and I've never seen anything in the software world this bad.  Except for FIX order state management.

The first problem, which we'd noticed when we looked at the house, was that the stopper didn't work, and hadn't worked since I first touched a computer.  Every now and then someone unfamiliar with the house would push it down, and then I'd have to get a knife out to lift it back in place.  Forcing repeat pusher downers to get their own knives prevented repeat occurrences.  The stopper couldn't be fixed because the pole for the stopper is in the ceramic box on the right.  Unlike modern, surviving sink designs, you cannot get to the stopper pull. 

You also cannot get to underneath the faucet, because it is blocked by the same ceramic box that keeps you away from the stopper pull.  Instead, the faucet is held against the sink with a butterfly-like anchor that you insert through the hole on the bottom and then screw up. The top hole is for the water supply.  Being the first person to view the wing nut in 90 years gave me the same queasy feeling I get when I look at gcc's codebase, and wonder, "Does this really work? But the {tests pass}/{water comes out}." It also turns out that no one --- and I mean no one still alive --- makes plumbing fixtures designed to fit this sink.  At one point Mary Anne said "Oh, so it is a four hole sink." No, no it is not. And Mary Anne claims to have realized that, too.

Once I took the faucet off, I was able to pull the whole assembly out:

It looks like something from an Alien movie.  The pipe on the right is the supply, and the long hooked rod is what (in some alternate world) moves the stopper up and down.

My offer to buy a 3D printer and print out a new faucet assembly was summarily rejected by Mary Anne.

A new pedestal sink is in our future.  90 years isn't a bad run.

Bits have width...

I'm working on generating custom gcode to carve topless boxes. The intent is to use them for a dresser I'm building for my daughter.

For my first test I did a bottom and a side; the side is the top piece.

The code for the boxes is up at https://github.com/razeh/gcode-boxes; unlike a lot of other box generators it generates straight gcode, without any intermediate vector representations.

It has two problems: it isn't take the width of the bit into account when it carves the indents, and it doesn't create an tabs for the sides.  I hadn't realized how important tabs are until the bottom piece dropped out from the plywood while the router was still moving.
  

Expanded z axis, new spindle

Over the last weekend, I upgraded my Z-axis.

I replaced the stock spindle with a more powerful DeWalt DW660, which included replacing the stock mounts with DW 660 mounts. I'd bought the DeWalt spindle and the mounts a while back; if I had to buy again today I'd buy a quiet cut spindle, so that I could control the spindle's speed from software.  

While I was at it, I also replaced the stock 200mm Makerslide with one of the 500mm sections from my original Shapeoko 2 kit.  I don't need the extra height now, but when I upgrade the X axis I will.

Both upgrades are working fine, but I'm still having problems with the cutting depth. When I try to carve a circle 1/2 an inch deep I only get a circle about 3/8 of an inch deep.  If I reduce the depth per pass from .028 inches per pass to .014 inches per pass it goes a bit deeper.  If I support the table under the spindle it goes even deeper.

I think there is too much flexibility in the current setup.  Right now there are two big sources of the flexibility.  

The first is that the 25mm by 50mm extrusions that make up the table have too much flex in them, given that they span 1800mm.  I'm going to deal with this by using some of the 25mm by 50mm extrusions as supports under the table instead of as the table surface. I'm also going to start using 25mm by 75mm extrusions for the table surface.  The 25mm by 75mm extrusions are a lot stiffer in 75mm axis (with a moment of inertia of 37cm⁴ vs 12cm⁴), and a bunch stiffer in the 25mm axis (3.1cm⁴ vs 4.5cm⁴) as well.  They also manage to be a little bit cheaper per surface area than the 25mm by 50mm extrusions because you don't need as much hardware to hook them up to the table.